Rotary cutting devices



1965 w. E. LIGHTFQOT EFAL 3,217,933

ROTARY CUTTING DEVICES 2 Sheets-Sheet 1 Original Filed Dec. 18. 1961 m W W w mw m T w Z W Wm B 1965 w. E. LIGHTFOOT ETAL 3,

ROTARY CUTTING DEVICES 2 Sheets-Sheet 2 Original Filed Dec. 18 1961 United States Patent 3,217,983 RUTARY QUTTENG DEVICELQ William E. Lightfoot, Box 432, and John H. Johnston, hath nf Alvarado, Tex. Continuation of application Ser. No. 159,924, Dec. 13, 1961. This application Aug. 9, 1963, Ser. No. 501,943 9 Claims. (Cl. 241-1tll) The present application is a continuation of our copending application Serial No. 159,924, filed December 18, 1961, now abandoned.

Our invention relates generally to rotary cutting devices and more particularly to cutting and shredding apparatus which is especially adaptable for cutting and shredding warm or cool, flexible, semi-flexible and resilient material in which one or more component elements may become adhesive under heat, such as asphalt shingle material.

From time to time and sometimes frequently in the business of manufacturing asphalt shingles of the type commonly used on roofs of buildings or as siding for buildings and other purposes, there is considerable unusuable such material which accumulates as waste and scrap. To dispose of such scrap and waste oftentimes becomes a serious problem to the manufacturer. Such waste and scrap material is either sold for a nominal price per load, or is simply dumped. The monetary loss can be substantial when large quantities of waste material must be disposed of in this manner.

It is recognized that the material per se in such waste and scrap has many possible uses, but the form in which it is presently available precludes its practical reuse. If such asphaltic scrap and waste could be cheaply and easily reduced to very small pieces, there are many applications where it could he profitably and effectively used.

One of the fundamental problems in shredding asphaltic materials is the tendency of such material to adhere and agglutinate when warm, causing clogging and jamming of the shredding apparatus.

Heretofore, and in the prior art of which we are aware there has not been available any entirely satisfactory device for cutting and shredding asphaltic material in the form of shingle waste and scrap. The devices of which we are aware are so constructed that they can cut and grind only fibrous or comminutable substances such as Wood, hay or grain and the like. None to our knowledge is satisfactory for cutting and shredding asphaltic materials, particularly when warm.

Accordingly, it is the general object of the invention to provide an improved and satisfactory device for cutting and shredding asphaltic shingle material.

Another object of the invention is to provide apparatus suitable for cutting and shredding asphaltic shingle and scrap material under all normally encountered temperature conditions.

Another object of the invention is to provide improved apparatus for cutting and shredding, on a continuous basis, scrap organic composite materials in sheet form one or more ingredients of which tends to become adhesive when heated.

Another object of the invention is to provide apparatus for the economical production of shredded material from asphaltic shingle scrap waste.

Briefly stated, the present invention in its broader aspects contemplates the provision of apparatus for cutting and shredding sheet-like organic composite materials one or more ingredients of which tends to become adhesive when heated, which apparatus includes a rotatable cutter head mounting cutter means having its peripheral surfaces disposed in adjacent spaced parallel relation to fixed cutter bar means. The apparatus also includes means for supporting and advancing the material to be shredded in a direction toward and substantially perpendicular to the cutter head rotational axis, with material hold down means provided above and in adjacent parallel spaced relation to the cutter bar means and in contact with the upper surface of the material. This hold down means preferably exerts pressure in a resilient manner on the material upper surface. Also, preferably, means are provided for continuously incising the material immediately ahead of the cutter bar means and in the direction of material movement.

For a further understanding of the invention and further objects, features, and advantages thereof, reference may now be had to the following description taken in corn junction with the accompanying drawings in which:

FIG. 1 is a schematic perspective view of an apparatus in accordance with a preferred embodiment of our invention;

FIG. 2 is a schematic perspective view of the apparatus of FIG. 1 with the housing removed, but with some parts omitted for the sake of clarity;

FIG. 3 is a fragmentary side elevational view of the apparatus of FIG. 2, and including portions of the frame and housing;

FIG. 4 is a schematic perspective view showing details of the upper plate portion of the apparatus of FIG. 2.

FIG. 5 is a cross sectional view showing details of the cutter head of the apparatus of FIG. 2.

Referring now to the drawings, FIG. '1 shows a schematic perspective view of the apparatus 11 of the present invention enveloped in a housing 13. FIG. 2 shows a schematic perspective view of the cutting and shredding device constructed in accordance with a preferred embodiment of the present invention, which device includes a support structure or frame 15, a feeding group 17, a shredding group 19, a fracturing group 21 and power group 23. It will be helpful to first describe each group separately and then the interaction of the several groups.

The feeding group 17 includes an endless feed belt 25, operating over an idler roller 27 and a drive roller 29, a gear reduction 31, an upper feed roller 33, a lower feed roller 35, a scoring assembly 37 and a guide plate 39.

The idler roller 27 rotates about its longitudinal axis on a horizontal shaft 41 which is axially fixed to and protrudes outwardly from each end of the idler roller 27. The drive roller 29 rotates about its longitudinal axis on a horizontal shaft 43 which is axially fixed to and protrudes outwardly from each end of the drive roller. The idler roller 27 and the drive roller 29 are of equal diameter and length and their respective shafts 41, 43 are supported by suitable bearings (not shown) attached to the sides of the support structure =15, such shafts having longitudinal axes lying in a common horizontal plane. The width of the endless feed belt portion 25 is approximately the length of the rollers over which it operates. The upper surface of the endless feed belt portion 25 lies generally in a horizontal plane parallel to the common horizontal plane of longitudinal axes of the idler roller 27 and the drive roller 25. Beneath and slightly in front of the drive roller 29 is the gear reduction 31 which is fixed adjacent the bottom and the near side of the support structure 15. The gear reduction 31 is driven by an electric motor which will be described presently as a part of the power group 23. A pinion 45 projects from the side of the gear reduction 31 and engages an idler gear 47 which in turn engages a gear 49 which is keyed to the shaft 43. Also, the idler gear 47 engages a gear 51 which is keyed to a shaft 53 of the lower feed roller 35. Vertically above the lower feed roller 35 there is the upper feed roller 33. The gear 51 which is keyed to the shaft 53 of the lower feed roller 35, engages a gear 55 which is keyed to a shaft 57 of the upper feed roller 33. The lower feed roller 35 and the upper feed roller 33 are 3 not contiguous, but are spaced apart a distance slightly less than the thickness of the asphalt scrap material, for a reason to be hereinafter explained. The top surface of the feed belt 25 and the upper margin of the cylindrical lower feed roller 35 are located at substantially the same level.

Directly above the drive roller 29 there is a horizontal shaft 59 having its longitudinal axis parallel to the longitudinal axis of the drive roller, to which shaft 59 are fixed a plurality of circular knives 61 held in spaced apart relationship by suitable spacer means (not shown). The circular knives 61 are secured to the shaft 59 by suitable retainer nut member 63:. The shaft 59 and the circular knives 61 thereon aresupported by suitable bearings (not shown) attached to the support structure 15.

A flat guide plate 39 is attached to the support structure immediately above and parallel to the general plane of the feed belt 25. The guide plate 39 is pierced by a plurality of rectangular slots -55, each directly beneath a respective circular knife 61. Each slot 65 is slightly wider than the thickness of the respective circular knife 61 and slightly longer than the chordal length of the segmental portion of the circular knife 61 intercepted by the plane of the top of such guide plate The shredding group 19 includes a cutter head assemblage 67 (see FIG. 5), an upper plate assemblage 69 (see FIG. 4), a cutter bar or anvil 71, a lower plate 73 and an upper plate support structure 75.

The cutter head assemblage 67, shown in FIG. 5, includes a horizontal metal cylinder 77, preferably of steel, extending longitudinally the width of the feed belt 25. A semi-segmental prism has been removed from each quadrant of such cylinder 77 forming thereby in each quadrant a long shoulder surface '79 and a short shoulder surface 81, each such surface being disposed perpendicularly to the corresponding shoulder surface in the preceding quadrant. A flat cutter knife blade 83 having a beveled cutting edge 85 is placed against the short shoulder surface 81 and extends radially beyond the peripheral surface of cylinder 77. The cutter knife blade 83 is held securely against the short shoulder surface 31 by a plurality of fasteners 87. A rotatable shaft member 78 projects longitudinally and axially from each end of the cylinder 77 and is supported by suitable bearings (not shown) attached to the support structure 15. The shaft member 73 extends beyond the bearings for a purpose to be hereinafter described.

Diametrically above and below the cylinder 77 and diametrically opposite the cutter knife blade 83 which is functioning at any instant, there is a respective horizontal metal wiper support bar 89, preferably of steel, extending longitudinally between the sides of the support structure 15. A wiper strip 91 is mounted on each wiper bar 89 between a U-shaped retainer strip 93, and is secured thereto by fasteners 97. The wiper support bar 89 is located in spaced relation to the cutter knife blade 553 so that as the cutter knife blade 83 rotates it brushes against the wiper strip 91. The wiper strip is made of a tough, resilient material such as leather or oil-resistant rubber.

The upper plate assemblage 69 (see FIG. 4) is located behind the upper feed roller and includes a stationary support plate 99 which extends horizontally and parallel to the upper feed roller 33, and is held in spaced relationship above the plane tangent to the bottom of the upper feed roller portion by a plurality of integrally connected threaded bolt members 101. The bottom surface of the stationary support plate 99 has an upwardly curved taper at its front edge portion, while the rear edge of the support plate 99 is square cut. The upper portion of the support plate 99 is provided with a plurality of rectangular recesses or notches (not shown) which are disposed at spaced intervals along the upper rear portion of the support plate 99. Each notch extends from the support plate rear edge to near its center, and the support plate thickness at the notches is reduced by approximately one half. A plurality of hinge journals 163, not necessarily of equal length, are integrally fixed to the top surface of the support plate 99 at regular intervals. Each hinge journal 183 and all taken together have an axial aperture 165 drilled therethrough. Midway between each adjacent pair of hinge journals M3 and near the back edge of the support plate 99 there is a bolt member 107 having one end fixed to the support plate 99, the threaded other end extending upwardly and inclining slightly toward the front part thereof. Th upper plate assemblage 69 includes also a plurality of'T-shaped flap portions 199 having an integrally attached hinge arm Ill extending along each side of the stem of such T-shaped flap portion ltl9. Each hinge arm lll merges with a hinge journal 113 having an axial aperture 115 the same diameter as the axial aperture 1%. The stem part of the T-shaped flap portion matches in shape and size the respective notch in the support plate 99 and is approximately as thick as the depth of such notch. A hinge shaft 117 is fitted in the axial apertures 105, 115 and through all other such apertures. The flap portion 109 has an oval aperture 119 out therein midway between the hinge arms 3111. The bolt member ltd? projecting through the oval aperture 119 in the flap portion N9, is surrounded by a compression spring 121, the lower end of which bears against the top surface of the flap portion 169 while the upper end bears against a washer 123 that is held in position by a nut member 1255 threaded on the bolt member 1637. The head part of the T-shaped flap portion M39 is slightly thicker than the support plate portion 99 so that the bottom surface of the head part is below the bottom surface of the support plate 99-.

The support structure 75 for the upper plate assemblage 69 is a heavy metal member, preferably of steel, approximately square in cross section, extending horizon tally and fastened securely to the sides of the support structure 15 above the upper plate assemblage 69. There are two apertures in the upper plate support structure 75 through which the bolt members Till are respectively inserted. A lower nut 127 together with an upper nut 129 provide means for holding the upper plate support assemblage 69 in spaced relationship with respect to the cutter bar 71.

The fracturing group 21 includes an upper slide portion 131, a lower slide portion 133 and a fracturing roller portion 135. The upper slide portion is made of metal, preferably steel, and is coextensive longitudinally with the lower plate 73. The upper longitudinal edge part of the upper slide portion 131 is bent at an angle forming a flange 137 which is affixed to the underside of the lower plate '73 by suitable fasteners (not shown). The lower part of the upper slide portion 131 extends downwardly at an angle and merges with the upper edge of the lower slide portion 133. The upper part of the lower slide portion 133 is curved to the same general contour as the fracturing roller portion 135. The lower part of the lower slide portion 133 projects downwardly and tangentially from the curved upper part to meet the plane of the bottom of the support structure extended. The fracturing roller portion 135 includes a rotatable cylindrical member 139 extending longitudinally parallel to the cutter knife blades 33 and situated below and to the rear of the cutter head assemblage 67, and a shaft member 141 projecting longitudinally and axially from each end of the cylindrical member 139; the shaft member 14-1 being supported by suitable bearings (not shown) attached to the support structure 15'. Also, the cylindrical member 1139 has multiplicity of short rod-like members 143 that protrude radially from its surface. The rod-like members 143 lie in two mutually perpendicular planes and are so spaced that the rod members in one plane are dis posed between the rod members in the other plane. The cylindrical member 139 is spaced in relationship to the curved upper part of the lower slide portion 133 so that the extremities of the rod members closely approach, but

J do not touch, the surface of the curved upper part white the cylindrical member 139 rotates.

The power group 23 includes a motor 145 located hori- Zontally between the sides of the support structure 15 and connected to the gear reduction 31 by a motor shaft (not shown). A shaft 147 protrudes from the gear reduction 31 horizontally in a direction opposite to the motor shaft and is supported at the opposed side of the support structure 15 by a bearing (not shown). An integral extension of the shaft 147 projects outwardly beyond the bearing member a suflicient'distance to permit the attachment thereon of a pulley 149. Also, a pulley 151 is attached to an integral extension of the shaft member 78 so that the pulleys 149, 151 are axially aligned. An endless belt 153 surrounds pulleys 149, 151 and thereby operatively connects the shaft 147 and the shaft member 78.

There is a pulley (not shown) attached to the opposed end of shaft member 57 which extends beyond the bearing (not shown) and also there is a pulley (not shown) attached to the end of shaft 59 which extends beyond the bearing (not shgwn). An endless belt (not shown) surrounds these pulleys and thereby operatively connects shafts 57, 59.

The shaft 147 extends through the gear reduction 31 and on the extended part thereof a pulley 155 is attached. A pulley 157 is attached to the extended end of shaft member 141 and disposed axially in line with the pulley 155. An endless belt 159 surrounds pulleys 155, 157 thereby operatively connecting shaft 147 and shaft member 141.

It is to be clearly understood that, wherever belts and pulleys are mentioned in this specification, means other than such belts and pulleys may be employed equally well, such means being chains and sprockets, gears and the like. Said pulleys, if used, may be of the cone pulley type or the single groove type and it is not to be inferred that either type is exclusively preferred because shown on the drawing, as each or both may be used effectively.

The manner in which the rotary cutting device of the present invention is used, will now be described. The scrap asphaltic material 161 which is to be shredded, is placed on the top surface of the feed belt 25. Electric energy delivered to the motor 145 causes it to rotate and, by means of the gear reduction 31, the pinion 45 rotates. The gears intermeshing with pinion d rotate and move the feed, belt 25 and the scrap asphaltic material 161 thereon forwardly, which is in the direction toward the cutter head assemblage 67. The scrap asphaltic material 161 passes between the feed belt 25 and the guide plate 39, and in so doing is incised by the circular knives 61 in a longitudinal direction. The scrap asp'haltic material continues to move forward and is directed between the upper feed roller 33 and the lower feed roller 35. Continuing in the same direction, the incised scrap asphaltic material 161 passes between the upper plate assemblage 69 and the cutter bar or anvil 71. It is important that the compression springs 121 be so adjusted that the upper plate 69 will press upon and restrain slightly the asphaltic material 161 as it passes under the upper plate and over the cutter bar or anvil 71. This is to prevent the material from being jerked through by the action of the cutter knife blade without being cut. As the incised scrap asphaltic material 161 emerges therefrom it is shredded by the cuttter knife blades 83 rotating about shaft member 78. The shredded material falls upon and slides down the inclined upper slide 131. When such material reaches the curved upper part of the lower slide portion it is further broken up by the fracturing roller portion 135 and in particular by the rotating rod-like members 143. The shredded scrap asphaltic material 161 accumulates behind the fracturing roller portion 135.

The drawings together with the foregoing disclosure describe a device which will effectively cut and shred asphaltic materials with no build-up gumming on the cutter knife blades 83 under most normal conditions of operation. It is evident to those skilled in the art that, while the cutter knife blades 83 are rotating at a moderately high speed, and when properly adjusted, the beveled cutting edge 85 of each blade strikes a plurality of wiper strips 91, which action Wipes away and removes immediately any build-up gumming. Furthermore, the cutter knife blades are partially cooled while rotating rapidly which also reduces the build-up gumming.

While the device illustrated in the drawings shows a cutter head assemblage 67 having four cutter elements 83, it is to be understood that the shape and location of the elements is not so limited. If desired, the cutter head may be made in such a manner that the cutter knife blades or elements are integral with the head itself. Also, two diametrically opposed cutter knife blades, or any suitable number may be used provided a rotational dynamic balance is maintained. The cutter elements may be made without a beveled cutting edge, but it is preferred that they have a sharpened edge as described hereinbefore. Likewise, the cutter bar or anvil 71 has been shown in the drawings having a fiat rectangular cross sectional shape. This, too, should not be considered a limitation. If desired, the cutter bar or anvil 71 may have a diamond, oval or a circular cross sectional form, but the rectangular shape is preferred.

Similarly, the fracturing roller need not be limited to the configuration shown in the drawing. It may be made sectionally so that adjacent sections together with the rod members thereon rotate oppositely, or it may be made with a square, oval, diamond or other regular cross sectional form. The rod members 143 themselves may be either curved or straight, but the straight type are preferred.

We have found that liquids or other substances which might reduce the build-up gurnming tendency are not necessary. However, it is recognized, that under some circumstances and conditions a liquid or other substance might be beneficial. If such is the case, a container with a dispenser may be attached to the device in a suitable manner.

It is preferred that the feed rollers 33, 35 be placed as close to the drive roller 29 as may be practicable. Likewise it is preferred that the cutter bar or anvil 71 in association with the upper plate 69 and the cutter head 67 be as close to the feed rollers as may be practicable. If desired, a plate or other means (not shown) may be located between the lower feed roller 35 .and the feed belt 25 to support the material advancing from the feed belt toward the feed rollers.

While we have shown our invention in only one form it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

We claim:

1. Apparatus for cutting and shredding sheet-like organic composite material one or more ingredients of which tends to become adhesive when heated, comprising in combination: a support structure, a rotatable cutter head journaled to said support structure and including a plurality of elongated cutter elements, means journaled to said support structure for supporting and advancing said material in a direction toward and substantially perpendicular to the axis of said cutter head, means mounted to said support structure in front of said cutter head for continuously incising said material in the direction of material movement, an elongated cutter bar disposed parallel to the axis of said cutter head and in spaced relationship adjacent the front periphery of said rotating cutter elements, rotatable fracturing means disposed beyond and in spaced relationship to said cutter head, means for transferring said material to said fracturing means, driving means for rotating said cutter head at a predetermined speed relative to that of the material advancing means, and an upper plate disposed above and 7 in adjacent parallel spaced relation to said cutter bar so as to contact the upper surface of said material, said upper plate being mounted on support means attached to said support structure.

2. Apparatus for cutting and shredding sheet-like organic composite material one or more ingredients of which tends to become adhesive when heated, comprising in combination: a support structure, a rotatable cutter head journaled to said support structure and including a plurality of elongated cutter elements, a plurality of wiper strips fixed relative to said support structure and disposed parallel to and impinging against said cutter elements, means journaled to said support structure for supporting and advancing said material in a direction toward and substantially perpendicular to the axis of said cutter head, means mounted to said support structure in front of said cutter head for continuously incising said material in the direction of material movement, an elongated cutter bar disposed parallel to the axis of said cutter head and in spaced relationship adjacent the front periphery of said rotating cutter elements, and driving means for rotating said cutter head at a predetermined speed relative to that of the material advancing means.

3. Apparatus for cutting and shredding sheet-like organic composite material one or more ingredients of which tends to become adhesive when heated, comprising in combination: a support structure, a rotatable cutter head journaled to said support structure and including a plurality of elongated cutter elements, means journaled to said support structure for supporting and advancing said material in a direction toward and substantially perpendicular to the axis of said cutter head, means mounted to said support structure in front of said cutter head for continuously incising said material in the direction of material movement, an elongated cutter bar disposed parallel to the axis of said cutter head and in spaced relationship adjacent the front periphery of said rotating cutter elements, a pair of rotatable feed rollers disposed parallel to and in front of said cutter bar with said rollers being arranged one above the other in spaced relationship and journaled to said support structure, driving means for rotating said cutter head at a predetermined speed relative to that of the material advancing means, and an upper plate assembly disposed above and in adjacent parallel spaced relation to said cutter bar and including means for resiliently contacting the upper surface of said material, said upper plate assembly being mounted on support means attached to said support structure.

4. The combination as set forth by claim 2 wherein a pair of rotatable feed rollers are disposed parallel to and in front of said cutter bar, said rollers being arranged one above the other in spaced relationship and journaled to said support structure.

5. The combination as set forth by claim 4 wherein an upper plate is disposed above, parallel to and in spaced relation to said cutter bar, said upper plate being fixed relative to said support structure.

6. Apparatus for cutting and shredding sheet-like organic composite material one or more ingredients of which tends to become adhesive when heated, comprising in combination: a support structure, a rotatable cutter head journaled to said support structure and including a plurality of elongated cutter elements, a plurality of wiper strips fixed relative to said support structure and disposed parallel to and impinging against said cutter elements, means journaled to said support structure for supporting and advancing said material in a direction toward and substantially perpendicular to the axis of said cutter head, means mounted to said support structure in front of said cutter head for continuously incising said material in the direction of material movement, an elongated cutter bar disposed parallel to the axis of said cutter head and in spaced relationship adjacent the front periphery of said rotating cutter elements, rotatable fracturing means disposed beyond and in spaced relationship to said cutter head, means for transferring said material to said fracturing means, and driving means for rotating said cutter head at a predetermined speed relative to that of the material advancing means.

7. Apparatus for cutting and shredding sheet-like organic composite material one or more ingredients of which tends to become adhesive when heated, comprising in combination: a support structure, a rotatable cutter head journaled to said support structure and including a plurality of elongated cutter elements, means journaled to said support structure for supporting and advancing said material in a direction toward and substantially perpendicular to the axis of said cutter head, a pair of rotatable feed rollers disposed parallel to and in front of said cutter bar with said rollers being arranged one above the other in spaced relationship and journaled to said supporting structure, means mounted to said support structure in front of said cutter head for continuously incising said material in the direction of material movement, an elongated cutter bar disposed parallel to the axis of said cutter head and in spaced relationship adjacent the front periphery of said rotating cutter elements, rotatable fracturing means disposed beyond and in spaced relationship to said cutter head, means for transferring said material to said fracturing means, driving means for rotating said cutter head at a predetermined speed relative to that of the material advancing means, and an upper plate assembly disposed above and in adjacent parallel spaced relation to said cutter bar and including means for resiliently contacting the upper surface of said material, said upper plate assembly being mounted on support means attached to said support structure.

8. The combination as set forth by claim 6 wherein a pair of rotatable feed rollers are disposed parallel to and in front of said cutter bar, said rollers being arranged one above the other in spaced relationship and journaled to said support structure.

9. The combination as set forth by claim 8 wherein an upper plate is disposed above, parallel to and in spaced relation to said cutter bar, said upper plate being mounted on support means attached to said support structure.

References Cited by the Examiner UNITED STATES PATENTS 1,679,883 8/1928 Speer 83-408 1,762,330 6/1930 Fielder et a1. 83408 X 1,776,593 9/1930 Meyer 146-107 X 1,797,950 3/1931 Forman 83-408 1,957,190 5/1934 Wood 14G102 2,311,692 2/1943 Potdevin 83-168 X 2,327,679 8/1943 Swenson 241-167 X 2,812,815 11/1957 Quinsey et a1. 83906 X 3,060,778 10/1962 Karber 14678 X ROBERT C. RIORDON, Primary Examiner. 

6. APPARATUS FOR CUTTING AND SHREDDING SHEET-LIKE ORGANIC COMPOSITE MATERIAL ONE OR MORE INGREDIENTS OF WHICH TENDS TO BECOME ADHESIVE WHEN HEATED, COMPRISING IN COMBINATION: A SUPPORT STRUCTURE, A ROTATABLE CUTTER HEAD JOURNALED TO SAID SUPPORT STRUCTURE AND INCLUDING A PLURALITY OF ELONGATED CUTTER ELEMENTS, A PLURALITY OF WIPER STRIPS FIXED RELATIVE TO SAID SUPPORT STRUCTURE AND DISPOSED PARALLEL TO AND IMPINGING AGAINST SAID CUTTER ELEMENTS, MEANS JOURNALED TO SAID SUPPORT STRUCTURE FOR SUPPORTING AND ADVANCING SAID MATERIAL IN A DIRECTION TOWARD AND SUBSTANTIALLY PERPENDICULR TO THE AXIS OF SAID CUTTER HEAD, MEANS MOUNTED TO SAID SUPPORT STRUCTURE IN FRONT OF SAID CUTTER HEAD FOR CONTINUOUSLY INCISING SAID MATERIAL IN THE DIRECTION OF MATERIAL MOVEMENT, AN ELONGATED CUTTER BAR DISPOSED PARALLEL TO THE AXIS OF SAID CUTTER HEAD AND IN SPACED RELATIONSHIP ADJACENT THE FRONT PERIPHERY OF SAID ROTATING CUTTER ELEMENTS, ROTATABLE FRACTURING MEANS DISPOSED BEYOND AND IN SPACED RELATIONSHIP TO SAID CUTTER HEAD, MEANS FOR TRANSFERRING SAID MATERIAL TO SAID FRACTURING MEANS, AND DRIVING MEANS FOR ROTATING SAID CUTTER HEAD AT A PREDETERMINED SPEED RELATIVE TO THAT OF THE MATERIAL ADVANCING MEANS. 